SPECIFICATION OF SAFETY-RELATED COMMUNICATION REQUIREMENTS IN HIGH AIR-TRAFFIC DENSITY AIRSPACE TO BE MET BY A FUTURE AMSS
(AERONAUTICAL MOBILE SATELLITE SYSTEM)

DRAFT 0.2

26.03.01


TABLE OF CONTENTS

FOREWORD

CHAPTER 1 introduction

1.1Scope

1.2Introductory context and expectations

1.2.1Benefits expected from a future AMSS

1.2.2Human Machine Interface Adaptation Challenge:

1.3Applicable ICAO standards and recommended practices

1.4Reference documents:

1.4.1EURONCONTROL ODIAC-defined requirements on datalink services

1.4.2RTCA documents, e.g. NGSS MOPS and (future) MASPS

1.4.3Other references

1.5Glossary

CHAPTER 2 Assumptions on applicable operations concepts

2.1Air Traffic Services

2.2Airlines Operational Communications

CHAPTER 3 Regulatory requirements

3.1General

CHAPTER 4 Architecture/system requirements

4.1Users group organisation:

4.2Radio-resources allocation and management

4.3Position of the AMSS architecture in the global communication infrastructure

4.4Geographical Scope

4.5Migration requirements

chapter 5 Functional and performance requirements

5.1AMS[R]S services capabilities and priorities

5.2Voice over data priority

5.3DATA Communication priority levels

5.4Addressed and broadcast modes of communications :

5.5Communication initial log-on

5.6Communication service transfer from one ATC unit to another.

5.7Communication set-up and delay performance:

5.7.1VOICE service, in the Ground to Air direction

5.7.2VOICE service , in the Air to Ground direction:

5.7.3DATA service in the ground to air direction: short messages

5.7.4DATA service in the ground to air direction : long messages

5.7.5DATA service in the air to ground direction : short messages

5.7.6DATA service in the air to ground direction: long messages

5.8VOICE Service Quality

5.8.1Intelligibility and users’ voice recognition

5.9Residual Error Rate , in both directions of propagation

5.10Connection resilience

5.11Security:

5.12Number of aircraft to be simultaneously served

5.13Communication loading : VOICE service

5.14Communication loading per aircraft: DATA service

5.15Service availability

CHAPTER 6 Reference model of traffic loading applicable to

6.1the European “core” airspace of high traffic density

6.2the US North-Eastern corridor

6.3Foreseeable evolution of the traffic for the time horizon considered

FOREWORD

  1. This document, prepared by EUROCAE Working Group 55 “Satellite Aeronautical Communication”, was accepted by the Council of EUROCAE on TBD.
  2. EUROCAE is an international non-profit making organisation, Membership is open to European users and manufacturers of equipment for aeronautics, trade associations, national civil aviation administrations and, under certain conditions, non-European organisations. Its work programme is principally directed to the preparation of performance specifications and guidance documents for civil aviation equipment, for adoption and use at European and world-wide levels.
  3. The findings of EUROCAE are resolved after discussion among its members and in co-operation with RTCA Inc., Washington DC, USA and/or the Society of Automotive Engineers (SAE), Warrendale PA, USA through their appropriate committees.
  4. This document has been achieved in coordination with TBD.
  5. EUROCAE documents are recommendations only. EUROCAE is not an official body of the European Governments; its recommendations are valid as statements of official policy only when adopted by a particular or conference of governments.
  6. Copies of this documents may be obtained from:

EUROCAE

17 rue Hamelin

75783 PARIS Cedex 16

FRANCE

Phone: 33 1 45 05 71 88

Fax: 33 1 45 05 72 30

E-mail:

Internet:

1

CHAPTER 1introduction

1.1Scope

This document specifies the mandatory requirements applicable to and key features expected from a future satellite-based aeronautical communication system, designated as AMSS[1], under both ITU and ICAO terminology. These requirements, unless otherwise noted are meant to be indifferently applicable to satellite and land-based systems and need to be considered on an end to end basis.

This document is to be viewed as belonging to a suite of standards and guidance documentation applicable to NGSS (Next generation Satellite System) comprising:

The (future) ICAO ANNEX 10 Chapter on NGSS

The NGSS MASPS, as currently being generated by RTCA SC-165

Specific satellite system MOPS

1.2Introductory context and expectations

1.2.1Benefits expected from a future AMSS

Compared to today’s aviation VHF and satellite-based AMSS infrastructures, such a system will provide for the following benefits:

a)High performance: its performance level will be adequate to serve high air-traffic density airspace regions , e.g. typical of Central Europe ( so-called “Core Area”) and the U.S. north-eastern corridor, in terms of communication set-up times and delays, as well as capacity to accommodate air-traffic, at the projected levels beyond year 2010 and throughout an aircraft whole flight phase profile[2],

b)Both VOICE and DATA services, with voice priority over data -
These two services will be provided in a highly integrated application and radio sharing environment, thus allowing more efficient HMI, hence greater end-users’ comfort and confidence, and accordingly, enhanced ATM safety and operation productivity,

c)Segregation of the ATM applications level from communication infrastructure: it will provide a communication architecture, at the service/application upper levels, capable of supporting an ATM airspace organisation optimised for air-traffic flow efficiency, independently from the radio architecture and resources (e.g. frequencies) management constraints inherent with today’s VHF analogue system,

d)SECURE Communications: It will bring in secure communication capabilities by providing robustness to spurious signal interference and protective features to guard against intrusion by unauthorised users, including possible use of encryption techniques,

e)relief of VHF band (119-137 MHz) congestion pressures:

  • Over both Europe’s “Core Area” and the U.S north-east corridor airspace, ATS organisations, facing pressure in meeting relentless air-traffic growth, are busy seeking to increase ATC capacity by “airspace resectorization”, and by deploying new computer-assisted tools to increase ATC Officers’ productivity. The former results into new ATC sectors and demand for new VHF radio-telephony frequency assignments . There is now however the serious issue on how to deal with the shortage of available VHF frequencies, predicted to arise by year 2005 , and to become critical , by 2010,[3]
  • A possible workaround such a serious issue is to introduce Satellite Communications, starting with upper En-Route airspace, as an alternative to VHF R/T, with the objectives of:
  • freeing up today's VHF frequencies for re-use in lower airspace ATC sectors[4]. and given that those upper sectors require significantly less area protection , the frequency reuse gain would even be more significant.
  • providing instantaneous and large-scale regional service-coverage in continuity with oceanic coverages
  • Acceptability of a satellite-based approach by all the ATM stake-holders, to mitigate the predicted VHF congestion , depend on many considerations, the most prominent of which being economics and overall dependability. Assuming that SATCOM would be positioned as a primary, but not as sole means of communications, dependability can be obtained by providing “hot redundancy”, with a minimum oftwo satellites in view of any aeronautical mobile and availability of a “back-up” terrestrial communication system, such as today’s VHF[5].

1.2.2Human Machine Interface Adaptation Challenge:

  • The future integrated voice and data environment raises a new challenge compared to today’s ATCO’s[6] HMI[7] and work methods, which will have to be adapted to integrate new HMI features and new ATCOs’ work procedures,
  • In parallel to the requirements for an AMSS design to take into account the herein set of specifications, there is the need to engage in the corresponding Human Factors studies and HMI design as early as possible in order to validate technical development choices and generate the resulting training and operating procedures:
  • The transition from the existing «manual»,analogue and fragmented aeronautical communication infrastructure to the future one, will have to be initiated as early as possible to get practical experience and “feedback” from operators, controllers and pilots.

1.3Applicable ICAO standards and recommendED PRACTICES

ICAO, Annex 10, Part 1 VOL3, (future) Chapter 12 : “Alternative Provision for Aeronautical Mobile Satellite [R] Service “

1.4Reference documents:

1.4.1EURONCONTROL ODIAC-defined requirements on datalink services

EUROCONTROL ODIAC report: OPR.ET1.ST05.1000-ORD-01-00 (Operational requirements for ATM air-ground communication data services)

1.4.2RTCA documents, e.g. NGSS MOPS and (future) MASPS

1.4.3Other references

ICAO AMCP/4 report, Appendix B to the Report on Agenda Item 4: “ Requirements and desirable features for a future ATS air-ground Communication System”

RTCA SC-172 paper, dated Nov; 17, 1994 : VHF AIR-GROUND Communication system improvements : Alternatives Study and Selection of proposals for future action

ESA/SDLS/AO/1-3222/97/NL/US, Annex 1, “Service requirements specification (from SDLS Expert group

1.5Glossary

A/C / Aircraft
ACARS / Aircraft Communications Addressing and Reporting System
ACM / ATC Communications Management
ACSE / Association Control Service Element
ADAP / Automated Downlink of Airborne Parameters
ADS / Automatic Dependent Surveillance
ADS-B / Automatic Dependent Surveillance - Broadcast
AEEC / Aeronautical Electronics Engineering Committee
AFN / ATS Facilities Notification
AMCP / Aeronautical Mobile Communication Panel
AMSS / Aeronautical Mobile Satellite Service
AOC / Airline Operations Control
ASAS / Airborne Separation Assurance System
ASCII / American national Standard Code for Information Interchange
ASN.1 / Abstract Syntax Notation
ATC / Air Traffic Control
ATI / ATIS delivery message
ATIS / Air Traffic Information Service
ATN / Aeronautical Telecommunication Network
ATR / ATIS Request
ATS / Air Traffic Services
ATSU / Air Traffic Services Unit
BIS / Boundary Intermediate System
CAP / Controller Access Parameters
CDA / DCL clearance echoback message
CIC / Clearance and Information Communications
CLA / oceanic clearance echoback
CLD / DCL clearance
CLNP / ConnectionLess Network Protocol
CLX / oceanic clearance message
CM / Context Management
CMC / Central Maintenance Computer
CPDLC / Controller-Pilot Data Link Communication
CRC / Cyclic Redundancy Check
DCL / Departure CLearance
D-FIS / Data link Flight Information Services
DLIC / Data Link Initiation Capability
D-OTIS / Data link Operational Terminal Information Service
D-RVR / Data link Runway Visual Range
DSC / DownStream Clearances
D-SIGMET / Data link SIGnificant METeorological information
DYNAV / DYNamic route AVailability
EC / European Commission
EMERALD / EMERging RTD Activities of reLevance for ATM concept Definition
EMERTA / EMERging Technologies opportunities, issues and impact on ATM
ETA / Estimated Time of Arrival
EUROCONTROL / The European Organisation for the safety of Air Navigation
FANS / Future Air Navigation Systems
FIR / Flight Information Region
FLIPCY / FLIght Plan ConsistencY
FSM / logical response message
HF / High Frequency
ICAO / International Civil Aviation Organisation
IMI / Imbedded Message Identifier
INMARSAT / INternational MARitime SATellite organisation
ISO / International Standardisation Organisation
LACK / Logical ACKnowledgement
LAR / Logical Acknowledgement Requirement
LEO / Low Earth Orbit
LREF / Local REference Function
MASPS / Minimum Aviation System Performance
MCDU / Multipurpose Control and Display Unit
MEN / Message Element Number
METAR / METeorological Aviation routine weather Report
MID / Message Identification Number
MOPs / Minimum Operational Performance Standards
MRN / Message Reference Number
MRT / Monitoring R/T
MWO / Meteorological Watch Offices
NGSS / Next Generation Satellite Services
NOTAM / NOtice To AirMen
NSAP / Network Service Access Point
OCM / Oceanic Clearance Message
ODIAC / operational requirements for initial air-ground data communication services
OOOI / Out, Off, On, In
ORQ / D-OTIS request
OTD / D-OTIS delivery message
OTT / D-OTIS termination request
PAM / Pilot Acknowledgement Message
PDU / Packet Data Unit
PER / Packet Encoding Rules
PFR / Post Flight Report
RCD / DCL request
RCL / Oceanic clearance request
RTCA / Requirements and Technical Concepts for Aviation
RTI / D-RVR delivery message
RTR / D-RVR request
RTT / Round-Trip Time
RTT / D-RVR termination message
SARPs / Standard And Recommended Practices
SATCOM / SATellite COMmunication
SMI / D-SIGMET delivery message
SMR / D-SIGMET request
SMT / D-SIGMET termination message
SNDCF / SubNetwork Dependant Convergence Facility
SNOWTAM / Notice To AirMen - SNOW
TCP / Trajectory Change Point
TMA / Terminal Manoeuvring Area
VCI / Voice Change Instruction
VDL / VHF Digital Link
VHF / Very High Frequency
WGS / World Global coordinates System
WP / Work Package
WPR / WayPoint Reporting

CHAPTER 2Assumptions on applicable operations concepts

2.1Air Traffic Services

2.2Airlines Operational Communications

CHAPTER 3Regulatory requirements

3.1General

  • The communication system shall be designed and operated in accordance with applicable Aviation standards, starting with ICAO Annex 10 SARPS
  • The system should preferably benefit from an ITU (International telecommunications Union) allocation as exclusive primary.
  • The system shall comply with ITU and other international standards (e.g. ETSI) as regards Electromagnetic Compatibility with all other ITU spectrum users.
  • The System shall be verified for performance and compliance with above defined standards , by test and analysis in accordance with the verification requirements set forth in an established MOPS approved by States Aircraft certification authorities.

CHAPTER 4Architecture/system requirements

4.1Users group organisation:

All air-ground communications are conducted within a private group of a/c users ,- i.e. an ATC_Unit , which comprises one ATC sector or a group of sectors. One group shall consist of up to [30] aircraft users - associated to an ATC “sector”, or group of sectors - and one ATCO[8] user

4.2Radio-resources allocation and management

The system shall be designed and operated as to permit the designation and grouping of aircraft users in accordance with airspace sectorization rules, in a manner unconstrained by the management of radio resources.

This is with the objective to allow the addressing and routing of communications to their intended end-users ( pilots, on-board systems, controllers and ground systems ) at end-users’ application level - independently from the system radio-resources management( e.g carrier frequencies, TDMA slots, CDMA codes, etc ) which will remain a “system” function, i.e. managed at the physical and link layers level, transparentlyto both ground and a/c users

NOTE :1. Group organisation/designation are expected to be performed by assigning a given group-identifier to a common set of a/c users within a group (ATC sector or group of sectors)
2. Within a group , each a/c user will be assigned a specific aircraft –identifier on the basis of the a/c flight number identifier (“call sign”) traceable to the a/c ICAO 24 bits designator

4.3Position of the AMSS architecture in the global communication infrastructure

I mean: should AMSS be the sole mean, or if not, what could be the foreseeable configuration (geographic, layered, dedicated to specific services (such as voice or broadcast, ...) ...) ?x

4.4Geographical Scope

4.5Migration requirements

chapter 5Functional and performance requirements

Preamble: all figures appearing within square brackets ( [xy]) are tentative and need further discussion and possible future work to achieve stability.

5.1AMS[R]S services capabilities and priorities

If the communication system offers both ATS[9] and AOC[10] service capabilities, it shall be designed and operated as to offer priority of ATS over AOC. To that end it shall incorporate suitable mechanisms to enforce Priority, Precedence and Pre-emption if necessary, for ATS communications over all other categories (AOC, AAC[11], APC[12]) in compliance with the priority rules defined by ITU and ICAO Annex 10 for safety-related communications ( refer to table XXX)

5.2Voice over data priority

The communication system shall offer simultaneous access to voice and data services, with priority to voice over data

5.3DATA Communication priority levels

The communication system shall be designed and operated such that it shall:

a)provide at least 3 levels of priority

b)support prioritization of messages consistent with ICAO, Annex 10, Vol II, Chapter 5

5.4Addressed and broadcast modes of communications :

The communication system shall permit :

  • Air-groundpoint to point (addressed) communication,

NOTE : this is expected to be the most common communication mode

  • Ground to air multicast mode , for VOICE Communications only

NOTE : Typically from one ATCO to all a/c within a group/ATC_unit, upon an ATCO initiation

  • Air to air multicast mode, in parallel to air-ground point to point comms

NOTE : communications from a given a/c is copied to all other a/c within that group, upon ATCO's initiation and control

  • Air to ground broadcast mode , for DATA services

NOTE : Two broadcast modes shall be provided:

  1. Limited to one or more (less than 10) groups/sectors of users, as support to ATIS[13] and TIS-B[14]
  2. General, on a distinct communication channel with continuous transmission of contents (e.g. weather or radar picture data ) periodically updated

5.5Communication initial log-on

This initial log-on is expected to be carried out by the aircraft side. It is needed and common to both VOICE and DATA communication services.

The communication system shall be designed and operated such that successful completion of aircraft log-on will take place in less than [30]seconds upon initiation , at 95 % and less than [60] seconds, at 99.999 % percentile

5.6Communication service transferfrom one ATC unit to another.

At any one moment throughout its flight progression an aircraft is continuously within the ATC responsibility of one ATC unit, and only one , (This unit may comprise one ATC sector or group of sectors, manned by a given team of ATC Officers). For this ATC responsibility to be safely carried out, it requires that an ATC communications channel, in the functional sense, be set-up, between a given a/c and an ATC unit, and be maintained available for use either by on-board or on-ground initiation, on a continuous basis. Furthermore, from the aircraft point of view, this ATC communication channel will be nominally be restricted, with that ATC unit, under which control that aircraft happens to fly at a given moment.

The communication system shall be designed and operated to permit the transfer of ATC responsibility from one ATC unit , to another downstream ATC unit. This transfer shall be accomplished by changing the aircraft/ATC_unit designators assignment at the ATC application level, under the following conditions:

a)The transfer is to be jointly enabled by the “new" , i;e.downstream”, i.e. aircraft- incoming , ATC unit and the preceeding one, upon initiation by either one of them, following appropriate mutual coordination

b)the transfer of responsibility/ATC-communication channel is to be achieved in less than [1 to 5] seconds, including the receipt of acknowledgement by the preceeding group/ATC sector,

c)the transfer shall be completed upon a/c user’s initiation and shall take less than [1 to 2] seconds for completion, including receipt of acknowledgement by the a/c user

5.7Communication set-up and delay performance:

5.7.1VOICE service, in the Ground to Air direction

The communication system shall be designed and operated such that, once the “ATC communication channel” , defined under para 5.5, has been established: